Catalyst
Definition and meaning of Catalyst in chemistry.
A catalyst is a substance that increases the rate of a chemical reaction without itself being used up in the process. It works by lowering the activation energy, offering an alternative reaction pathway so that a greater proportion of collisions are successful.
In more detail
A catalyst does not change the position of equilibrium or the amount of product that can form; it only helps the reaction reach that point faster by speeding up the forward and reverse reactions equally. Catalysts may be homogeneous (in the same phase as the reactants) or heterogeneous (in a different phase). They are vital in industry, iron catalyzes the Haber process that makes ammonia, and in living things, where enzymes act as highly efficient biological catalysts.
Key facts
| Effect | Lowers the activation energy |
|---|---|
| Used up? | No, it is regenerated |
| Main types | Homogeneous, heterogeneous |
| Field | Physical chemistry |
In a car's catalytic converter, platinum and palladium catalyze the conversion of toxic carbon monoxide into carbon dioxide.
Frequently asked questions
Is a catalyst used up in a chemical reaction?
No. A catalyst takes part in the reaction but is regenerated by the end, so it is not consumed. A small amount can catalyze the conversion of a large quantity of reactant.
What is the difference between a catalyst and an enzyme?
An enzyme is a biological catalyst, usually a protein, that works inside living organisms. All enzymes are catalysts, but not all catalysts are enzymes.